requestAnimationFrame: what exactly is the timestamp?

Question

I have always thought that timestamp used by requestAnimationFrame is the same as usual timestamp in JavaScript, that is number of milliseconds since January 1st, 1970. Today I

Answer 1

It's a DOMHighResTimeStamp or a high-resolution timestamp (the same you get with window.performance.now()).

The time stamp is:

current time for when requestAnimationFrame starts to fire callbacks.

The main difference between an ordinary timestamp and high-res timestamp is:

DOMTimeStamp only has millisecond precision, but DOMHighResTimeStamp has a minimal precision of ten microseconds.

Note: some browsers do not implement this aspect of rAF yet and may give you faulty or no value as argument.

Some resources:

• requestAnimationFrame
• DOMHighResTimeStamp